\psset{unit=0.5,algebraic}
\begin{pspicture*}(-3,-1)(3,5)
\psaxes[labelFontSize=\scriptstyle,ticksize=-3pt 0,labelsep=2pt]{<->}(0,0)(-3,-1)(3,5)
\psplot[linecolor=blue]{-3}{-0.0001}{2.7182^(1/x)}
\psplot[linecolor=blue]{0.1}{3}{2.7182^(1/x)}
\footnotesize
\rput[l](0.5,0.5){$f(x)=e^{1/x}$}
\end{pspicture*}